Boring drill bit



FIG. 1 is a bottom perspective view thereof;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a side elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a top perspective view thereof.

The broken line showing of a boring drill holder bit in FIG. 1 is intended for the purpose of illustrating environment and forms no part of the claimed design. 

The ornamental design for a boring drill bit, as shown and described. 